The present invention relates to shafts and, more particularly, to stub arbor shafts, which shafts may be attached and detached to and from members such as large rolls supported by the shafts.
One commercially important use for such shafts is in paper mills where a plurality of rolls of paper are loaded onto a cutting machine and supported on suitable shafts while being cut into sheets. Customarily, each roll is mounted on a bearing at each end of the roll. Shafts of the subject type support the rolls on the bearings. Conventionally, one of the bearings can be reciprocated in the axial direction of the roll and the other bearing can be rotated about a vertical axis in order to align the rolls. The cutting machine runs essentially continuously and while empty rolls are being replaced, the machine is fed from other rolls. On a typical machine, there are six rolls disposed in three rows of two each.
At present it is more time-consuming and a more tedious job to repair this shaft, than the shaft of this application. The ends of the shafts, which extend into the roll, have outer annular rubber bushings. Provision is made in the shaft's construction to compress the bushings axially thereby causing them to bow outwardly into tighter fit within the roll. When the rubber bushing wears, it is necessary to take the shafts apart to replace the bushings. The prior art shafts have the further disadvantage that tools are required to fix the shafts, for example, to replace the bushings, and this entails further labor expense since it is deemed maintenance according to most union contracts, and thus should be done by the maintenance staff and not by the machine's normal work force.
In the existing prior art structure, it is necessary to almost completely disassemble the shaft in order to replace the bushing.
For example, in one prior art shaft structure, snap rings are employed which require special plyers for their removal. Then it is necessary to remove cotter pins and nuts on a rod which extends through the shaft, and then unscrew the cone. Only thereafter can the shaft be disassembled to remove the bushing. The use of snap rings is also disadvantageous since there is the possibility of snap rings coming out during use if improperly installed.